Fuel pump for internal combustion engines



May 19, 1936. K. J. E. HEssELMAN FUEL PUMP FOR INTERNAL COMBUSTIONENG'NES 2 Sheets-Sheet 1 original Filed May 2o, 1951 /A I I Uff/V WW y,ATTORNEY May 19, 1936.

K. J. E. HESSELMAN FUEL PUMP FOR INTERNAL coMBUsTIoN ENGINES OriginalFiled May 20, 1931 2 Sheets-Sheet 2 lli .2.

.9 59 57 fig N .Al/r4 www BY y f-@ZJ Patented May 19, 1936 UNITED STATESFUEL PUMP FOR. INTERNAL COIVIBUSTION ENGINES- Knut Jonas EliasHesselman, Saltsjo-Storangen,

Sweden ApplicatonMay 20, 1931, Serial No. 538,756.

Renewed September 24, 1935.

vember 7, 192'?` 40 Claims.

This application is a continuing application in `respect to myco-pending applications Serial Nos. 315,957 filed October 30, 1928(Patent No.

1,912,367 granted June 6, 1933); 473,332 filed August 8, 1930 (PatentNo. 1,835,490 granted December 8, 1931) and 483,833 led September 23,1930 (Patent No. 1,949,470 granted March 6,1934); and is to beconsidered as relating back so far as herein continued, to the aforesaidapplications for all dates and rights incident to the filing thereof.

The present invention relates to fuel pumps for internal combustionengines of the type driven by liquid fuel and has particular referenceto pumps for engines of such type which are provided with cylindervalves operated through the medium of an engine driven cam shaft.

A major object of the present invention is to provide an improved formof pump construction in which one or more fuel pumps are driven from theengine cam shaft and in which the casing of each pump is provided with aprojecting journaled part adapted to be seated in the cylinder castingin such a way as to absorb the torque resulting from the pressure due toactuation of the pump plunger. Other objects of the invention, togetherwith its more specific nature and the advantages to be derived from itsuse will best be understood from the following detailedy description ofa preferred embodiment which is illustrated in the accompanying drawingsforming a part of this specification.

In the drawings,

Fig. 1 is a side elevation of a pump embodying the invention mounted inan engine which is shown partly in end elevation and partly intransverse vertical cross section;

Fig. 2 is a central longitudinal section on an enlarged scale of thepump shown invFig. 1;

Fig. 3 is a section of a part of the pump shown in Fig. 2 with the partsillustrated in a different position;

Fig. 4 is a front elevation illustrating mounting r of a plurality ofpumps in a'multi-cylinder en- 4" gine; and,

Fig. 5 is a diagrammatic illustration showing the manner of connectinga, plurality of pumps in a. multi-,cylinder engine.

Turning now to Fig. 1 reference numeral I indicates the engine cylinderand 2 the cylinder head in an internal combustion engine having a crankcase 3 in which is mounted the main crank shaft 4 and the usual camshaft 5. `Piston 6 connected to crank shaft 4 bymeans of connecting r 5orod 'I is located in cylinder I and air for com- In Sweden No- (Cl.12S-139) bustion is admitted to the combustion chamber 8 and exhaustgases are expelled therefrom through the medium of inlet and exhaustvalves located in the cylinder head 2. These valves are ordinarilyalined axially of the motor and in the 5 gure one of the valves isindicated at 9.

Inlet and exhaust valves for the cylinder are l closed by means ofsprings I0 and are" opened by rocker arms 4II which are actuated bycamsV I2 on shaft 5 through the medium of vertical push 10 rods I3.

Cam shaft 5 is driven from crank shaft 4 by any suitable means such forexample, as the Vusual cam shaft gear or chain drive indicated in dottedlines at I4. 15

The cam shaft 5 is utilized to actuate the fuel pumps as well as tooperate the engine Valves. In engines requiring a plurality of pumps theconstruction and arrangement of the several pumps With respect to thecam shaft is the same and I 20 will, therefore describe only theconstruction 0f one such pump. l

For the purpose of actuating the pump the cam shaft 5 is provided with acam I5 acting on a tappet I6 which extends upwardly and outwardly 25 -apartition extending substantially parallel to the axis of the camshaft'and enclosing the space 30 alongside the cylinder through whichthe tappets I6 extend. A spring'IQ seated between suitable shoulders onthe plate I8 and the tappet I6 operates to keep the tappet in constantcontact with the face of cam I5. As will be explained more in 35 detaillater, the construction of the pump is such that the tappet I6 operatesto actuate the pump von its delivery stroke, the suction stroke of thepump being effected by spring action.

Referring to Fig. 2, the pump is shown therein 40 in detail. Itcomprises a casing 20 having two projecting arms 2I and 22, these armsbeing preferably at right angles to each other. Arm 2l provides acylindrical journal adapted Yto seat in a cooperating bore 23 in theside of the cylinder 45 casting, and arm 22 'provides a bore 24 for thereception of the pump plunger 25. The end of plunger- 25 extending-beyond arm 22 is provided withga head 26, the lower face of which isadapted to be directly contacted by the upper end of the 50 tappet I6.The upper face of head 26 acts as a retainer for a spring 21, thisspring operating to actuate the pump plunger on the suction stroke. Y gn The partition plate I8 is provided with out- 55 wardly extending ears28 carrying the rotatably mounted shaft 29, thisshaft being situatedoutside of the arm 22 ofthe pump casing. Shaft 29 is provided with anarm 36 adapted to contact the lower face of the plunger head 26 to limitthe length of the suction stroke of the pump. In order to vary thelength of the suction stroke of the pump, shaft 29 is rotated by meansof a lever 3| or the like which may be controlled either by hand or bymeans of a suitable speed governor. Opposite the head 26 the shaft 29 isgrooved as at 32 for a purpose which will be explained later.

Arm 22 is threaded at 33 and over this threaded portion there is screweda sleeve 34 having an inwardly turned flange 35 at its lower end, theinne'r diameter of this flange being somewhat less than the diameter ofthe collar 36 forming the upper portion of head 26. portion 33 the arm22 is provided with a cylindrical recess 31 into which projects a key38. Key

38 is removably seated in an opening in the sleeve` 35' and is retainedin position by Va spring steel clip 39 seating in a suitable externalgroove in sleeve 34. The bore 24 communicates at its upper end with thepump chamber 40 which, it is to be noted, is considerably below thelevel of the center line of the arm 2|.

Opening laterally into the pump chamber 40 is the inlet passage 4|controlled by the pump inlet valve |12. Valve 42 seats against ahardened seat in a sleeve 43 which is seated in the bore of a threadedplug 44 screwed into a suitable recess in the main body portion of thecasing. A second sleeve 45 having an inturned flange at its inner end,acts as a retaining member for the valve spring 46. Sleeves 44 and 45are'preferably a tight fit in plug 44 so that upon removal of this plugthe entire .valve assembly will be removable as a unit. A removable plug41 screwed in the outer wall of the casing provides means for insertingand removing the inlet valve assembly.

The delivery channel leading from the pump chamber 40 .is in the form ofa small diameter bore 48 preferably in alinement with the inlet passage4|. n at the axis of arm 2| by means of a substantially verticallyextending bore 50 closed at its upper end by means of plugl 5|. Becauseof the diiilculty of making a small diameter bore of sufilcient lengthto extend to the end of the arm 2|, the outer end of this arm is boredto a relatively large diameter as at 52 and a plug 53 is inserted inthis ibore, this plug having a bore 54 there- YYthrough of the samediameter as and registering with the bore 49.

In the outer end of bore 52 are two dischargel or delivery valveassemblies 55, each of these assemblies comprising a ball valve seatedagainst a suitable tubular seat-forming member 56 by means of a spring51. vOutside of the outermost delivery valve assembly is an annular plug58 which provides an abutment for the outer valve spring 51 to bearagainst and which also serves to center the injection nozzle 59 carriedat the end of the arm 2|. 'I'he plug 58 serves as a centering means byengaging a recess in the face of the plate-like base 60 of nozzle 59.Nozzle 59 is secured to theI .end of arm 2| by means of a cap 6| screwedover y the externally threaded end of arm 2| and engagingA the base 60of the nozzle. Cap 6| is provided with a tubular extension 62 whichserves to protect the relatively delicate tubular portion Above thethreaded Bore 48 is connected with bore 49 nozzle assembly is removedfrom the engine.

Nozzle 59 is provided with one or more fuel delivering orifices 64 andin order to prevent rotation of the nozzle when cap 6| is screwed intoposition (which rotation might throw the delivery orice or orices out oftheir proper position) the base of the nozzleI is provided with aprojection or lug 65 adapted to engage a suitable notch 66 in the endwall of the arm 2|.

The pump casing 20 provides an oil inlet chamber 61 having an oil inletat 68 and an oil'outlet at 69. 1

' The casing also carries a pump release valve 10 arranged-to interruptthe effective delivery or discharge stroke of the pump plunger and toreturn the oil,Y displaced by the plunger after the release valve isopened to the suction side of the pump. The valve seat for the releasevalve y1|! is preferably formed by a separate plate 1| of' hardenedsteel or other suitable material held in place within the pump casing bya distance piece 12 against which the inner end of a retaining sleeve 13which is screwed into the casing abuts. Th.' distance piece 12 isprovided with a plurality of ports or openings 14 .aording communicationwith a channel 15 in the pump casing whichleads to the inlet chamber 61.Valve 10 has a. downwardly projecting stem 16 adapted to be contacted bythe inner end of plunger 25 before the latter reaches the end of. itsdischarge stroke for thev purpose of lifting the valve determining theeiective discharge stroke of the plunger. It will be noted thatclearance is provided between the stem 16 and the valve seat member 1|so that oil may flow freely from the pump chamber 40 to the inletchamber 61 upon opening o`f valve 1|). Valve 10 is provided with anupwardly extending stem in the form of a plunger 1-1 slidably mounted inthe sleeve 13 which serves as a guide. An external spiral groove 18 isprovided on the plunger 11, this groove operating to permit the escapeof air from the pump chamber when valve 10 is'opened.

The release valve is closed by means of a spring 19 compressed between aspring retaining ring 88 and the lower flange of a cup shaped springretaining member 8| resting on a suitable shoulder 'I'he manner in whichthe pump is held in posi-v tion in the cylinder will be largely obviousfrom Fig. 1. In order to facilitate insertion and removal of the arm 2|in the cylinder bore 23, this arm is preferably provided with two spacedcylindrical Journals 81 and 88, the latter being of slightly largerdiameter than the former. 'I'hese journals are made aclose sliding fitwithin corresponding portions of the bore 23 and between these journalsthe diameter of the arm 2| may be made.somewhat smaller as at 89.

In order to prevent rotational displacement of the pump after it ismounted, the cylinder castlng carries a projecting pin 96 adapted toseat in a corresponding recess 9| in the pump casing.

In multi-cylinder engines when two or more pumps are employed they mayadvantageously be held in position in pairs (as shown in Fig. 4) bymeans of clamps 92 through which anchoring studs 93 secured to thecylinder block pass. Other suitable means may, however be employed forremovably securing the pumps in position.

I prefer to supply the pumps with oil by means of a circulating systemand have illustrated such a circulating supply system in Fig. 5. Thearrangement shown in Ythe gure comprises a feed conduit 94 supplied bymeans of any suitable form of engine driven pump 95 and a return conduit96 for returning excess fuel to the supply tank. The

engine illustrated is of the conventional six cylinder type and it willbe observed that the several pumps are connected in parallel between thevconduits 94 and 96 by means of branch inlet conduits 91 and branchdischarge conduits 98. It will also be observed that oil is suppliedthrough conduit 94 at one end of the motor and is returned by way ofconduit-96 from the opposite end of the motor, this arrangement aiordingthe most even distribution of ow through the several pumps.

The operation of the pump will be largely evident from the foregoingdescription. Oil is drawn into the pump chamber 4U on the suction strokeof the plunger from the supply chamber 61 and on the discharge stroke isdelivered through the injection nozzle 59 until the upper end of theplunger contacts the stem 16 on the releasing valve to lift the valveand terminate the eiective discharge stroke. The length of stern 16 issuch that valve 10 is opened by the pump plunger while the latter isstill traveling at a relatively high velocity and the consequent suddenrelease in pressure provides for sudden cessation of ow through theinjection nozzle at a time when the oil is flowing therethrough at highvelocity. This prevents poor atomization due to deceleration of ow atthe end of the injection period.

It will be apparent that when the release valve 'lll is opened by thepump plunger, the oil thereafter returned from the pump chamber to .theinlet chamber 61 during the remainder of the upward stroke of the pumpplunger will tend to pro-- duce pressure pulsations within chamber 81.In order to eliminate such pulsations the diaphragm 84 is provided. Acirculating oil supply system such as is shown in Fig. 5 will tend tokeep the inlet chamber 81 under a slight pressure and a spring such asspring 85 is preferably employed in conjunction with such a system forthe purpose of balancing the normal constant pressure maintained inchamber 8T by the circulating pump 95.

The removal of air from the oil is highly important and in the vform ofpump herein illustrated any air carried into the pump is eifectivelyremoved from the pump chamber. `As will be observed from Fig. 2, therelease valve 'l0 is at the upper end of the pump chamber where any aircarried into the chamber will automatically tend to collect. The upperend of this chamber is opened upon each discharge stroke of the pump sothat air has no opportunity to remain within the pump chamber. Wheneverthe release valve is opened a free passage for ow of air is providedthrough the groove 18 and openings 82 to the upper part o f chamber 61from which the air is carried to gether with the excess oil through theoutlet 69 communicating with the branch outlet pipe 98.

Regulation of the amount of oil delivered for each stroke of the pumpplunger is governed by varying the length of the intake stroke throughmovement of the control shaft 29.

It is highly important that the accuracy of the adjustment governing thestroke of the pump be not disturbed and one of the objects of thepresent invention is to provide a pump which may be readily removed forinspection or repair and then replaced without disturbing any adjustmentgoverning the quantity of fuel delivered by the pump. As will be evidentfrom the drawings the position of the pump is fixed by the seating ofarm 2| in the cylinder bore 23. This fixes the position of the releasevalve 'I0 governing the termination of the delivery stroke. Shaft 29 isrotatably fixed with respect to the cylinder and since the position ofthis shaft governs the .length of the suction stroke, it is importantthat it be maintained in accurate alinement.

When it is desired to remove the pump, the sleeve 34 onthe arm 22 isscrewed upwardly from the position shown in Fig. 2 to the positionshownin Fig. 3. lThis lifts the head 26 on the pump plunger above the levelof the bottom of the groove 32 in shaft 29 and upon release of theclamping means securing the pump to the cylinder block permits the pumpto be Withdrawn from the cylinder without necessitating removal of shaft29. The sleeve 34 may also be screwed into the position shown in Fig. 3in case it is desired to render the pump inoperative because of breakageof some part thereof or because of failure of the cylinder with whichthe pump is associated to function properly for any other cause.

The key 38 prevents the sleeve 34 from being inadvertently screwed offof the stem 22 and. providesa positive lock preventing the plunger fromfalling out of the pump with consequent damage, when the pump is removedfrom its operating position. Ii' it is desired to remove the pumpplunger for any reason this may readily be done by removing theretaining clip 39 and key 38 after which the sleeve 34 may be screwedoff and the plunger removed.

It is not necessary to remove the pump if it is desired to remove theinlet valve assembly. Removal of this assembly may readily beaccomplished merely byremoving the cover plate 99 and unscrewing theplugs 41 and 44.

The release valve assembly may readily be removed upon unscrewing thecover plate 83.

It Will be evident that the discharge valve and injection nozzleassembly may be readily disassembled by unscrewing the cap member 6|, itbeing of course obviously necessary to remove the pump before this canbe accomplished.

As will be evident from Fig. 1 the pump arrangement is extremelycompact, the pump or pumps being so positioned as to not interfere withother auxiliary equipment necessary for the engine. By placing the .pumpchamber at a level below that of the arm 2|, the entire pump may be keptbelow the level of the top of the cylinder and in a position where itdoes not in terfere with the usual intake or exhaust manifolding |00, atthe side of the cylinder head.

Due to the manner in which the arm 2| is mounted in the cylinder, itwill be evident that this arm is capable of readily absorbing the torqueor bending movements due to pressure created by the pump plunger, thuseliminating the dimculty arising from any part of. the mech-v anismbending or springing out of position due to forces encountered inoperation.

It will be apparent that many changes and modiflcations `may be madewithin the scope of the present invention, which is defined in theappended claims.

What I claim is:

1. A fuel injecting unit for internal combustion engines comprising acasing providing a pump chamber, an arm providing a journal adapted toseat. in an engine cylinder to fix the position of the pump, a dischargepassage leading from the pump chamber to the end of said arm, aninjection nozzle removably secured to the end of said arm and incommunication with said passage, a second arm having a borecommunicating with the pump chamber, a pump plunger in said bore, saidplunger having a portion projecting from said arm,4 and a sleeveadjustably mounted on the second mentioned arm and adapted to engage theprojecting portion of the plunger to hold the same in retractedposition.

2. A fuel pump of the plunger type for internal combustion enginescomprising a casing providing a pump chamber and a'fuel inlet chamber,an 'inlet valve and a release valve for providing communication betweenthe pump chamber and the inlet chamber, a pump plunger adapted tocontact said release valve to open the same during the discharge strokeof the plunger, a laterally projecting arm on said casing providing ajournal adapted to seat in an engine cylinder to fix the position of thepump, and a pump discharge passage leading from the pump chamber to theend of said arm.

3. A fuel pump for airless injection of fuel into internal combustionengines comprising .a pump casing having a pump chamber, a laterallyextending arm providing a journal adapted to seat in an engine cylinderto x the position of the pump, said arm having an axial bore ofrelatively large diameter extending inwardly from the outer end thereof,a pump discharge passage of relatively small diameter in said casingprovidingcommunication between the pump chamber and said bore,'and asleeve Within said bore, said sleeve having a small diameter boreregistering with one end of said discharge passage and providing acontinuation thereof to a point adjacent to the outer end of the arm.

4.v A fuel pump of the character described comprising a. casing having alaterally projecting arm adapted to seat in an engine cylinder to fixthe position of the pump, said arm having two spaced cylindrical bearingsurfaces, the outer of` .said surfaces being of smaller diameter thanthe inner surface and the diameter of the arm between said-surfacesbeing less than that of either of said surfaces, and means forpreventing said cylindrical bearing surfaces from turning with respecttothe cylinder in which they are seated.

5. A fuel pump of the plunger type for internal combustion enginescomprising a casing pro-y viding a pump chamber and an inlet chamber,

inlet and discharge passages communicating with the pump chamber, arelease valve above'said pump chamber providing communication betweenplaces in the pump chamber and in the inlet chamber above said passages,and a pump plunger extending into thepump chamber, said release valvehaving a part extending into said pump chamber and positioned so as tobe opened by the plunger on each discharge stroke thereof whereby toprovide a passage for escape of air from the pump chamber to the inletchamber upon opening of said release valve.

6. A fuel pump of the plunger type for internal combustion enginescomprising a casing providing a. -pump chamber and an inlet chamber,inlet and discharge passages communicating with the 'y pump chamber, arelease valve providing communication between said inlet chamber and apoint in the pump chamber above said passages, said release valvecomprising an upwardly extending stem and groove means providing achannel for escape of air from the pump chamber past said stem when therelease valve is opened.

'7. A liquid fuelpump of the plunger type for internal combustionengines comprisinga pump casing providing a pump chamber and an inletchamber, a release valve adapted to be opened by the pump plunger oneachv discharge strokethereof, said release valve comprising a stemextending into said inlet chamber, a spring locatedv in said inletchamber and a cup-shaped springretaining member engaging said stem forcausing said spring to close the release valve.

8. A liquid fuel pump for internal combustion engines comprising acasing providing a pump chamber and having inlet and outlet passagescommunicating with said chamber, a release valve for closing the upperend of said chamber above the level of said passages, a pump plunger, meins for reciprocating said plunger to cause it to directly open saidrelease valve at a xed point in the discharge stroke of the plunger, andmeansfor stopping the plunger at selected points during the suctionstroke of the plunger to meter the quantity of fuel drawn into the pump.

9. A fuel pump for internal combustion engines comprising a casingproviding a pump chamber and an inlet chamber, a valved inlet passagefor flow of fuel from the inlet chamber to the pump chamber, a passagefor flow of excess fuel and of air from the pump chamber to the inletchamber, said passage being arranged above the pump chamber so es toautomatically free it of air when the passage is opened, a release valveadapted to be opened by the pump plunger for controlling said last namedpassage, and means for circulating fuel through said inlet chamber.

l0. A fuel pump of the plunger type for internal combustion enginescomprising a casing providing a pump chamber and an inlet-chamber, meansprevidng for ow of fuel from the inlet chamv l chamber.

l1. A fuel pump of the plunger type. for internal combustion enginescomprising a casing providing a pump chamber and an inlet chamber, meansproviding for flow of fuel from the inlet chamber to the pump chamber,means for discharging excess fuel from the pump chamber to the inletchamber during the discharge stroke of the pump plunger, said inletchamber being defined in part by a. flexible diaphragm for absorbingpressure pulsations in the chamber due to return thereto of fuel fromthe pump chamber.

12. A fuel pumping system for internal combustion engines comprising apump of the plunger type having a pump chamberand a fuel inlet chamber,a pump release valve adapted to return culating fuel through said inletchamber, and

spring means acting on said diaphragm to balance the -pressure exertedthereon by the pressure required to circulate fuel through the inletchamber.

13. A fuel supply system for a multi-cylinder internal combustion engine.comprising a fuel pump for each cylinder, each of said pumps having alaterally extending arm journaled in a cylinder to fix the operativeposition of the pump with respect to the cylinder, and common clampingmeans for removably securing a plurality of pumps .in operativeposition.

14. In an internal combustion engine having a cylinder, a fuel pumphaving a casing providing a pump chamber and having an extensionremovably secured to the Wall of said cylinder to x the position of thepump casing with respect to the cylinder, a pump plunger projecting fromsaid casing, engine driven means for actuating said plunger, a rotatableshaft having an arm adapted to contact the end of said plunger toregulate the length of the suction stroke of the plunger, the axis ofsaid plunger passing between said shaft and said cylinder, and saidplunger being retractable to permit removal of the pump laterally fromthe cylinder past said shaft.

15. In an internal combustion engine, a cylin- Ader having inlet anddischarge valves, a cam shaft for operating said valves, a fuel pumphaving an arm journaled in the cylinder .to fix the position of the pumpwith respect to the cylinder, said pump comprising a plunger projectingfrom the pump casing, a tappet adapted to actuate said plunger bycontacting the projecting end thereof, a cam on said cam shaft foractuating said tappet, a control shaft located outside the axis of thetappet and the pump plunger, means associated with said shaft forcontrolling the length of the suction stroke of the plunger and meansfor holding said plunger in retracted position to permit removal of thepump past said 16. In aninternal combustion engine, a cylinder having acounterbored opening through the wall thereof, a fuel pump comprising anintegral body having a bore forming a pump chamber and an arm having ashoulder adapted to seat against the bottom of the counterbore andbearing sur- 17. In an internal combustion engine, a cylinder blockforming a plurality of cylinders, each having a counterbored openingthrough vthe wall thereof, a fuel pump for each cylinder comprising 'anintegral body having a bore forming apump chamber and an arm having ashoulder adapted to seat against the bottom of the counterbore andbearing surface adapted to engage the side wall of -said opening tocenter lthe pump with respect to the opening, there being a fueldischarge passage through said arm communicating with said chamber,common clamping -means for removably securing a plurality of pumps ,tosaid block, a plunger'reciprocable in each of said bores, means forreciprocating 'saidplungers, and control means operated by a commonmember for stopping the suction stroke of each of said plungers at aselected point.

18. In an internal combustion engine, a pluthrough the wall thereof, afuel pump for eachcylinder, each pump comprising a body having a boreforming a pump chamber and an arm adapted to seat in one of saidopenings to fix the position of the pump with respect to the cylinder, aplunger in each of said bores, means for removably securing said pumpsin position with said arms seating in said openings, means for causingreciprocation of the pump plungers, and control means operated by acommon member for stopping each of said plungers at like selected pointsin their respective suction strokes.

19. In an internalcombustion engine having a combustion chamber, thecombination with a cylinder having an opening through the wall thereofcommunicating with the combustion chamber, of a fuel pump comprising abody having a bore forming a pump chamber and an arm having a fueldischarge passage therethrough communicating with the pump chamber, saidbody having bearing surface for fixing the position of the pump with thearm in said opening, a valve seating in said body for relieving pressurein the pump chamber and havinga part extending into said chamber, aplunger-in said bore having an inner end adapted to contact the valvepart in said chamber to open said valve at a xed point in the dischargestroke of the plunger, means for actuating the plunger by contacting theouter end thereof, means for removably securing said pump in positionwith said arm in said opening,l

. ing a bore forming a pump chamber and an arm having a fuel dischargepassage therethrough communicating with the pump chamber, said armhaving bearing surfacev adapted to fix the vposition of the pump with-respect to the cylinder by seating against the side Wall of saidopening, a valve' seating in said body for relieving the pressure in thepump chamber and having a part extending into said chamber, a plunger insaid bore having an inner end adapted to contact the valve part in saidchamber to open said valve at a fixed point in the discharge stroke oftheV plunger, means for actuating the plunger by contacting the outerend thereof, means for removably securing said pump in positionwith saidarm in said opening, and control means for stopping the suction strokeof said plunger at selected points.

21. In an internal combustion engine having a combustion chamber, thecombination with a cylinder having an opening through the Wall thereofcommunicating with the combustion chamber, of a fuel pump comprising abody having abo`re forming a pump chamber and an armI having a fueldischarge passage therethrough communicating with the pump chamber, saidbody having bearing surface for fixing the position of the pump with thearm in said openingg;

an injection nozzle removably secured to the end of said arm and adaptedtoproject into said chamber when the pump is Iin iixed position, a

valveseating in said body for relieving pressure in the pump chamber andhaving a part extending into.- said chamber,` a Vplunger in said bore'having an inner end adapted to contact the valve part in said chamber toopen said valve at a combustion chamber, a cylinder having a cylindricalopening through the Wall thereof com-` municating with the combustionchamber, a fuel pump comprising a body having a bore forming a pumpchamber and a cylindrical arm having a. fuel discharge passagetherethrough communieating with the pump chamber, said arm havingbearing surface adapted to x the position" of the pump body with respectto the axis of said opening by seating against the wall thereof,

-means for removably securing said pump in position with said arm insaid opening, means for preventing turning movement of the pump bodyvwith respect to the opening, a fuel injection nozzle removably securedto the end of said arm and having an orifice for projecting fuel fromthe nozzle at an angle to the axis of s aid open'- ing, means forholding said nozzle in a predetermined position of rotation with respecttosaid arm, a plungerjn said bore, and means for actuating said plungerby contacting the outerl end thereof.

23. In a fuel injecting unit for internal combustion engines, a, bodyportion adapted to seat in an engine cylinder having a passagetherethrough for discharge of fuel, an injection nozzle, means forremovably clamping the injection nozzle to the end of said body portion,means for centering the nozzle with respect to said passage, means forinsuring the positioning of said nozzle in a given fixed position ofrotation with respect to said body portion, and means for insuring thepositioning of said body portion in a given xed position of rotationwith respect to the cylinder.

24, In afuel injecting unit for internal combustion engines, a bodyportion adapted to extend through the wall of an engine cylinder, saidbody portion having a bore for discharge of fuel and an end portion ofsaid bore being of substantially larger diameter than-necessary for thedischarge of fuel, an injection nozzle, means for removably clampingsaid nozzle to the end of said body portion and means for centering thenozzlewith respect to said bore comprisingI an annular element extendinginto said end portion of the bore and extending into a suitablecooperating recess in the nozzle.

25. In a fuel injecting unit for internal combustion engines, a bodyportion adapted to extend through the wall of an engine cylinder, saidbody portion having a bore for' discharge of fuel and an end portion ofsaid bore being of substantially larger diameter than necessary for thedischarge of fuel, an injection nozzle, an annular element in threadedengagement with said body portion for removably clamping said nozzle tothe end of the body portion and means for centering the nozzle withrespect to said bore comprising an annularv element extending into saidend portion of the bore and extending into -a suitable cooperatingrecess in the nozzle.

26. In a fuel'injecting unit for internal combustion engines, a bodyportion adapted to extendA through the Wall of an engine cylinder, saidbody portion having a bore for discharge of fuel and an end portion ofsaid bore being of substantially larger diameter than necessary for`theA discharge of fuel, an injection nozzle, means for removablyclamping said nozzle to the end of the body portion, and means forcentering the nozzle with respect to said bore comprising an annularelement extending into said end` portion of the bore andextending into asuitable cooperating recess in the nozzle, said nozzle and said bodyportion having cooperating surfaces for insuring the positioning of saidnozzle inA a given fixed position of rotation with respect to said bodyportion.

27. In a fuel injecting' unit for internal combustion engines, a bodyportion adapted to extend through the wall of an engine cylinder, saidbody portion having a bore for discharge of fuel and an end portion ofsaid bore being of substantially larger diameter than necessary for thedischarge of fuel, an injection nozzle, an annular element in threadedengagement with said body portion for removably clamping said nozzle-tothe end of said portion, and means for centering the nozzle with,

respect to said bore comprising an annular element extending into saidendr of the bore and extending into a suitable cooperating recess in thenozzle, said nozzle and said body portion having cooperating surfacesfor.v insuring the posi,- tioning of said nozzle in a given fixedpositionof rotation with respect to said body portion.

28. In a fuel injecting unit for internal combustion engines, a bodyportion adapted to extend through the Wall of an engine cylinder, saidbody portion having a bore for discharge of fuel and the major portionof said bore being of substan-i tially larger diameter than necessaryfor the discharge of fuel, a, plurality of tubular inserts in said boreincluding an endinsert projecting from the end of. said body portion, aninjection nozzle having arecess and means for removably" clamping saidinjection nozzle to the end of said'body portion, said end insertextending into said recess to center the nozzle.

29. In a'fuel injecting unit for internal combustion engines, a bodyportion adapted to extend through the wall of an engine cylinder, saidbody portion having a bore for discharge of fuel andthe major portion ofsaid bore being of substantially larger diameter than necessary for thedischargeof fuel, a plurality o1' tubular inserts in said bore includingan insert having discharge valve means therein and an end insertprojecting from the end of said body portion, an injection nozzle havling a recess, and means for removably clamping said injection nome tothe end of'said body portion, said end insert extending into said recessto center the nozzle.

, 30. In' a fuel pump of the plunger type for in-f ternal combustionengines,.a casing providingna pump chamber and an inlet chamber abovethe pump chamber, inlet and release valves providing communicationbetween said fchambers, a pump plunger,` said release valve beinglocated above the pump chamber and being adapted to be opened by saidplunger, said inlet valve being located laterally of the pump chamber,said casing having an opening in the side wall thereof for removal ofsaid inlet valve and a removable closuretor said opening.

31. In a fuel pump ,of the plunger type for in l ternal combustionengines, a pump casing providing a pump chamber andan inlet chamber ad-7o" jacent to said pump chamber, inlet and release l valves lproviding'communication-between said ,I

chambers, a guidey extending into said inlet cham-l` ber, said releasevalve having a steme'xtending through said guide, a-cup shaped springretainer engaging said stem, a spring in said inlet chamber engagingsaid retainer to seat the release valve, and a pump plunger adapted tolunseat the release valve to return excess fuel from the pump chamber tothe inlet chamber.

32. In a fuel pump of the plunger type for internal combustion engines,a pump casing providing a pump chamber and an inlet chamber adjacent tosaid pump chamber, inlet and release valves providing communicationbetween said chambers, a removable element providing a seat for therelease valve, a guide removably secured in said casing, said guideextending into said inlet chamber and serving to clamp said removableelement in position, said release valve having a stem extending throughsaid guide, a cup shaped spring retainer engaging said stem, a spring insaid inlet chamber engaging said retainer to seat the release valve, anda pump plunger adapted to unseat the release valve to return excess fuelfrom the pump chamber tothe inlet chamber. v

33. In a fuel pump of the plunger type for internal combustion engines,a pump casing providing a pump chamber and an inlet chamber adjacent tosaid pump chamber, inlet and release valves providing communicationbetween said chambers, an annular element at the end of the pump chamberproviding a seat for the release valve, a guide threaded into thecasing, said guide extending into said inlet chamber and serving toclamp said annular element in position, said release valve comprising ashouldered plunger having a pin portion projecting through said annularelement into the pump chamber and a plunger portion extending throughsaid guide, a spring retainer engaging said plunger portion, a spring inthe inlet chamber engaging said retainer to seat the release valve, anda pump plunger adapted to contact said pin portion to unseat the releasevalve whereby to return excess fuel from the pump chamber to the inletchamber.

34. In a fuel pump for internal combustion engines, a casing providing apurnp chamber and having an arm providing a cylinder for a pump plunger,a plunger in said cylinder having a portion projecting from the casing,a spring engaging the projecting portion of the plunger to move itoutwardly of the casing on its suction stroke, and an adjustable sleeveengaging said casing and the plunger vfor limiting outward movement ofthe plunger.

35. In a fuel pump for internal combustion engines, a casing providing apump chamber and having an arm providing a cylinder for a pump plunger,a plunger in said cylinder having a portion projecting from the casing,a spring engaging the projecting portion of the plunger to move itoutwardly 'of the casing on its suction stroke, and an adjustable sleevethreaded over said'arm and engaging the plunger for holding the plungerinwardly of the outer end of its stroke against the action of saidspring.

36. In a fuel pump for internal combustion engines, a casing providing apump chamber and having an arm providing a cylinder for a pump plunger,a plunger in said cylinder having a portion projectingfrom the casing, aspring engaging the projecting portion of the plunger to move itoutwardly of the casing on its suction stroke, a sleeve threaded oversaid arm and engaging the plunger for holding the plunger inwardly ofthe outer end of its stroke against the action of said spring, and meansproviding a stop for limiting the outward travel of said sleeve.

37. In a fuel pump for internal combustion engines, a casing providing apump chamber and having an arm providing a cylinder for a pump plunger,a plunger in said cylinder having a portion projecting from the casing,a spring engaging the projecting portion of the plunger to move itoutwardly of the casing on its suction stroke, a sleeve threaded oversaid arm and engaging the plunger for holding the plunger inwardly ofthe outer end of its stroke against the action of said spring, and meansproviding a stop for limiting the outward travel of said sleevecomprising an v annular recess in said arm and a part on said sleeveprojecting into said recess.

38. In a fuel pump for internal combustion engines, a casing providing apump chamber and having an arm providing a cylinder for a pump plunger,a plunger in said cylinder having a portion projecting from the lcasing,a spring engaging the projecting portion of the plunger to move itoutwardly of the casing on its suction stroke, a sleeve threaded oversaid arm and engaging the plunger for holding the plunger inwardly ofthe outer end of its stroke against the action of said spring, and meansproviding a stop for limiting the outward travel of said sleevecomprising an annular recess in said arm and a part on said sleeveprojecting into said recess, said part being removable from the sleeveto permit the sleeve to be screwed off the arm, whereby to permitremoval of the plunger from the casing.

39. In an internal combustion engine, a cylinderhaving a bore throughthe side wall thereof, a fuel pump comprising a casing having alaterally projecting arm providing a journal engaging the wall of saidbore, a pump plunger projecting from said. casing substantially at rightangles to said arm, engine driven means for forcing said plungerinwardly of the casing on its discharge stroke, means separate from thepump adapted to contact said plunger to control the length of thesuction stroke thereof, `the axis of Said plunger passing between thelast mentioned means and the cylinder, and means associated With thepump casing for holding the pump plunger in retracted position to permitremoval of said pump laterally of the cylinder.

40. In apparatus of the character described, a cylinder block having aplurality of cylinders, a bore through the side wall of each of twoadjacent cylinders, a fuel pump for each cylinder, each pump comprisingacasing ,having a laterally projecting arm providing a journal engagingthe wall of one of said bores, means providing cooperating abutmentsurfaces for preventing turning movement of the pumps about the axes oftheir respective arms, and a yoke engaging two adjacent pumps forremovably clamping the same in operative position to said cylinderblock.

KNUT JONAS ELIAS HESSELMAN.

